I didn't even understand if all women have penises or just the majority and what caused it.
As far as I know females exist, but futas were banished from the union and now concentrate on the periphery (and outside of that). So they might just have low numbers of females on PS10, a piracy ridden mining colony.
Idk what caused it but im perfectly happy that not being answered. People can imagine what sounds likely or fun for them. My best guess is an uptick in designer babies in the previous centuries. So humans designed a third gender.
A, It might have always been part of our reproduction cycle.
B, We might have made futas part of our reproduction cycle so they can naturally born now.
C, or maybe they cant, only with technology.
I like B, the union may have banished everyone who carry futa genes, because we know they banished their families too.
They just didnt fit in the mold the way the union imagined a stable society, most likely due to their ambitiousness, perhaps even agression and/or tendency for poligamy. Hence we can now get dicked nonstop on asteroids.